Daniel C. Arnold, a prominent Houston-area lawyer and businessman who worked behind the scenes to elevate some of the city's key institutions, died Tuesday. He was 88.

Arnold succumbed to kidney cancer surrounded by family at his Houston home.

During his career, Arnold helped launch the Urban League, secured federal funding to improve the city's public transportation system and mobilized the political will to create the Harris County Hospital District, the taxpayer-funded safety-net hospital system.

"He was bigger than life, a quiet bulldog," said Holcomb Crosswell, chairman of the Texas Medical Center board. "He wouldn't bite, but he won't let go of the bone either. He was relentless."

Marc Shapiro, former president of Texas Commerce, added that "he didn't like the spotlight, but he knew how to get things down He had that lawyer's ability to push people to do what needed to be done, but didn't want credit for it."

Arnold was a well-known figure in the Houston community, having served on the board of the Texas Medical Center from 1962 to 1989. He was a longtime member of the Baylor College of Medicine board of trustees, including a stint as chairman, and he was the chairman and president of First City Bancoroporation of Texas.

A native Houstonian, Arnold grew up during the Depression, enjoying what he said in 2010 interview was "a very normal childhood for that day and time. Those of us who grew up in this part of the country did not know what a Depression was or realize it to any extent."

His son, Steven Arnold, said in an interview Tuesday his father was "an incredible family guy" who loved the Houston Astros and being involved in his kids' and grandkids' lives. "He knew every teacher and every coach at every school that his kids went to and that his grandkids went to," Arnold said.

"He just had a way," Arnold said. "I don't know how to capture it, he just had a personality that was opening and welcoming, but he would also really test your mettle."

A 1953 graduate of the University of Texas-Austin's law school, Arnold later joined Vinson & Elkins, where he was a partner for 30 years and focused primarily on real estate.

"He was a brilliant lawyer and very hard driving in his work," said Harry Reasoner, a Vinson & Elkins partner and one of the state's best-known lawyers. "In his civic career, which he pursued in addition to being a major contributor to our law practice, he played key roles. When he left Vinson & Elkins, it was a real loss."

In 1962, at 32 years of age, Arnold joined what was then known as the City-County charity hospital system, which badly lacked funding. At one point, unable to secure funding from city officials, he went on a live local television newscast to draw attention to conditions at the old Jefferson Davis Hospital that led to an outbreak of staph infections.

As the board chairman, he led the effort to turn the system into the taxpayer-supported Harris County Hospital District (now known as the Harris Health System). The public referendum failed four times before it finally passed by a two-thirds vote in 1965. Arnold was the driving force.

"He was sort of the father of the hospital district," said Shapiro, also a Baylor College of Medicine board member.

Lois Moore, a former hospital district president, added that "he was a great champion, passionate and instrumental in the getting better care for the underserved."

Also a longtime Baylor board member — he was chairman from 1996 to 2001 — Arnold negotiated the original agreement by which Baylor provided the medical staff for Ben Taub Hospital and later helped write the bill that enabled the private medical school to obtain state funding from the Texas Legislature.

Arnold also helped co-found the Houston Area Urban League and was the chairman of Harris County's Metropolitan Transit Authority from 1980 to 1984.

Metro CEO Tom Lambert said he was deeply saddened to hear about the death of Arnold, who oversaw the transportation organization at a pivotal time for the city.

Lambert credited Arnold for helping re-make local transportation with an emphasis on cleanliness and riders.

"I very much respected him," Lambert said. "He was a qualified, caring, responsive and personable leader. I think the entire agency is saddened by his passing."